Apparatus for mixing gas and liquid

ABSTRACT

An apparatus for continuously mixing a liquid and a gas under pressure includes a body member having a chamber containing a freely moving ball. During operation, liquids entering the chamber impart rotation to the ball floating in the liquid. The rotating ball presents a continuously changing thin liquid layer to the gas entering the chamber above the liquid level for continuous mixing of the gas and the liquid.

Umted States Patent 1191 1111 3,917,756 Rice 1 1 Nov. 4, 1975 APPARATUS FOR MIXING GAS AND 1,799,252 4/1931 Roberge 261/18 B x LIQUID 2,095,485 10/1937 Bassett 137/539 x 2,955,608 10/1960 Stone 137/597 X Inventor; Warren Wesley Rice, wrightsville 3,507,741 4/1970 Aleixo... 161/175 Beach, N.C. 3,768,509 10/1973 Goda 137/539 [73] Assignee: E. I. Du Pont de Nemours & FOREIGN PATENTS OR APPLICATIONS Wllmmgton, 1,007,571 10/1965 United Kingdom 261/84 [22] Filed: June 11, 1974 Primary ExaminerTim R. Miles [21] Appl' 478400 Assistant ExaminerRichard L. Chiesa [52] US. Cl. 261/18 B; 239/432;2265l9//946 [57] ABSTRACT [51] Int 2 BOIF 3/04 An apparatus for continuously mixing a liquid and a [58] Field of A 84 112 gas under pressure includes a body member having a 261 /DIG. 26 9O chamber containing a freely moving ball. During oper- 259 4 ation, liquids entering the chamber impart rotatlon to 161/ 169/15 239/4132 the ball floating in the liquid. The rotating ball pres- [56] References Cited ents a continuously changing thin liquid layer to the gas entering the chamber above the liquid level for UNITED STATES PATENTS continuous mixing of the gas and the liquid. 710,718 10/1902 Seeger 239/432 X 788,764 5/1905 Fitton 239/432 x 3 Claims, 3 Drawmg Flgures US. Patent Nov. 4, 1975 FIG.

APPARATUS FOR MIXING GAS AND LIQUID BACKGROUND OF THE INVENTION The invention relates to an apparatus for continuously mixing a high pressure gas with one or more liquids. The apparatus is particularly useful in the continuous mixing of ingredients to prepare microcellular polymer structures by a flasher extrusion process.

A number of conventional mixing or blending devices are directed to the intermixing of two or more materials which are in liquid or gaseous states. A number of these devices comprise a container located in the main flow path of the liquid. A gaseous material is then directed through the container wherein the materials are intended to be mixed. This type blender is inherently incapable of regulating the concentration of the final mixed product. Accordingly, the ratio of liquid to gas in any given dispersed quantity is very irregular. A number of prior devices included structurally complex moving parts designed to improve the uniformity of concentration of the mixed dispersion. In the production of a dispersed mixture of a high pressure gas and a molten linear polypropylene polymer for the continuous coating of a composite filament, premixing of the high pressure gas inflatant with the molten polymer requires additional tanks, agitators, check valves and related plumbing.

SUMMARY OF THE INVENTION An apparatus for mixing a gas with a liquid comprising: an elongated body member having a chamber defined by upper and lower conical portions connected by a cylindrical portion; said upper and lower conical portions each terminating in an apex, there being an inlet passage leading into said upper conical portion and an outlet passage leading from the apex of the lower conical portion and at least one other passage leading into said lower conical portion; a ball located within said chamber and free to move from sealing contact with said lower to sealing contact with said upper conical portions; a source of pressurized gas connected to said inlet passage; and a source of pressurized liquid connected to said other passages in said lower conical portion, said pressure of said gas and said liquid being in balance whereby the liquid enters the chamber and causes the ball to rotate and carry a film of liquid on its surface to be contacted by the gas for continuously mixing the liquid with the gas, the gas/liquid mixture then exits the chamber through said outlet.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of the mixing apparatus of the invention.

FIG. 2 is a sectioned elevation taken along 2-2 of FIG. 1.

FIG. 3 is a plan view taken along 3-3 of FIG. 2 with the ball removed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing, the embodiment chosen for purposes of illustration includes an elongated capped body member 10. The body member contains a chamber 12 which is defined by upper and lower conical portions 14, 16, respectively, connected by a cylin-' drical portion 15. The upper and lower conical portions each terminate in an apex. An inlet 18 passage is connected to a source of pressurized gas (not shown) and leads into the chamber 12 through the apex of upper conical portion 14. An outlet passage 20 leads from the chamber 12 through theapex of lower conical portion 16 while two other inlet passages 22, 24 are connected to sources of pressurized liquids (not shown) and lead into chamber 12 through the walls of lower conical portion 16. A ball 26 is located within chamber 12 and is free to move within the confines of the chamber between the upper and lower conical portions of the chamber. When at its upper limit of travel, the ball seals off inlet passage 18 while at its lower limit of travel, the ball seals off inlets 22, 24 and outlet 20 by sealing contact with lower conical portion 16.

The preferred material for ball 26 is nylon polyamide resin which is slightly deformable to allow the ball to seal against the conical portions l4, 16 of chamber 12. The density of the ball is not critical and can be chosen to provide floatation on the liquid entering the inlets 22, 24. The choice of density of the sphere will depend on the density of the liquid as will be readily understood by one skilled in the art.

In operation, when liquid is introduced into the chamber through inlets 22, 24, ball 26 is displaced from sealing contact with the conical portion 16 of the chamber 12. The velocity of the entering liquid causes the ball to rotate. Rotation of the ball carries a film of liquid on its surface which is contacted by the gas entering inlet 18. This provides a freshly renewed surface of liquid on the ball and permits improved adsorption of the gas in the liquid.

So long as the pressure of the liquid supplied through inlet passages 22, 24 and the pressure of the gas supplied through inlet passage 18 are in balance, mixing of the liquid with the gas by ball 26 continuously occurs and permits the gas/liquid mixture to exit through outlet passage 20.

Supply of liquid is regulated by positive displacement pumps (not shown) feeding into the lower part of the chamber. Chamber pressure is regulated by the gas supply system through the inlet passage 18 and also by the outlet passage 20. Gas flow demand is governed by gas solubility in the liquid. Liquid level in the chamber determines if liquid and gas mix. Gas supply pressure failure lets liquid in the chamber rise and seals the sphere against the upper conical portion 14. Too little liquid in the chamber because of liquid supply failure seals the sphere against the lower conical portion 16.

What is claimed is:

1. An apparatus for mixing a gas with a liquid comprising: an elongated body member having a chamber defined by upper and lower conical portions connected by a cylindrical portion; said upper and lower conical portions each terminating in an apex, there being an inlet passage leading into said upper conical portion and an outlet passage leading from the apex of the lower conical portion and at least one other passage leading into said lower conical portion; a ball located within said chamber and free to move from sealing contact with said lower to sealing contact with said upper conical portions; a source of pressurized gas connected to said inlet passage; and a source of pressurized liquid connected to said other passages in said lower conical portion, said pressure of said gas and said liquid being in balance whereby the liquid enters the chamber and causes the ball to rotate and carry a film of liquid on its surface to be contacted by the gas for continuously mixing the liquid with the gas, the gas/liquid mixture then exits the chamber through said outlet. The apparatus as defined in claim there being I two other inlet passages leading into the lower conical 2. The apparatus as defined in cla|m I, said inlet pasportion sage leading into the apex of the upper conical portion. 

1. AN APPARATUS FOR MIXING A GAS WITH A LIQUID COMPRISING: AN ELONGATED BODY MEMBER HAVING A CHAMBER DEFINED BY UPPER AND LOWER CONICAL PORTIONS CONNECTED BY A CYLINDRICAL PORTION, SAID UPPER AND LOWER CONICAL PORTIONS EACH TERMINATING IN AN APEX,THERE BEING AN INLET PASSAGE LEADING INTO SAID UPPER CONICAL PORTION AND AN OUTLET PASSAGE LEADING FROM THE APEX OF THE LOWER CONICAL PORTION AND AT LEAST ONE OTHER PASSAGE LEADING INTO SAID LOWER CONICAL PORTION, A BALL LOCATED WITHIN SAID CHAMBER AND FREE TO MOVE FROM SEALING CONTACT WITH SAID LOWER SEALING CONTACT WITH SAID UPPER CONICAL PORTIONS, A SOURCE OF PRESSURIZED GAS CONNECTED TO SAID INLET PASSAGE, AND A SOURCE OF PRESSURIZED LIQUID CONNECTED TO SAID OTHER PASSAGES IN SAID LOWER CONICAL PORTION, SAID PRESSURE OF SAID GAS AND SAID LIQUID BEING IN BALANCE WHEREBY THE LIQUID ENTERS THE CHAMBER AND CAUSES THE BALL TO ROTATE AND CARRY A FILM OF LIQUID ON ITS SURFACE TO BE CONTACTED BY THE GAS FOR CONTINUOUSLY MIXING THE LIQUID WITH THE GAS, THE GAS/LIQUID MIXTURE THEN EXITS THE CHAMBER THROUGH SAID OUTLET.
 2. The apparatus as defined in claim 1, said inlet passage leading into the apex of the upper conical portion.
 3. The apparatus as defined in claim 2, theRe being two other inlet passages leading into the lower conical portion. 